1. Technical Field
The invention relates to a roll-flanging tool for flanging component parts, preferably for producing hemmed connections between two or more component parts. The tool is or can be fastened to an actuator which can be moved spatially, for example an end of an arm of an industrial robot, or other framework which is comparable with regard to the connection. The tool can in particular be used in the manufacture of vehicles and vehicle parts, preferably in the series production of automobiles.
2. Description of the Related Art
In automobiles, particular regions of the body, for example wheel arches, or attachment parts, for example sunroofs, engine bonnets and mudguards, are flanged in order to fixedly connect an inner part and an outer part of the body or attachment part in question to each other by means of a hemmed connection. The flanged component part—generally the outer part—is usually a metal sheet part. During flanging, a flanging roller travels a peripheral strip of the component part to be flanged, in the longitudinal direction, and folds over a flanging web which includes the periphery of the peripheral strip. If, for example, the flanging web is folded over by 90°, this is achieved in a plurality of consecutive flanging steps, as is described in EP 1 420 908 B1 for roll-flanging in a plurality of processing runs to be performed consecutively and in EP 1 685 915 for successively folding over in one processing run. Component parts in which the peripheral strip, along which a flanging web is to be folded over, points at an angle to an adjacent region of the component part, and in which the angular position of the peripheral strip changes in the longitudinal direction, are for example problematic with respect to accessibility and consequently the freedom of movement of an actuator bearing a roll-flanging tool. Thus, in one longitudinal portion, the peripheral strip can for example enclose an angle of 90° with the region of the component part which is adjacent in said portion, while another longitudinal portion encloses another angle with the region of the component part which is adjacent in said portion or for example simply extends the region in question in a straight line. The peripheral strip can be continuously twisted in the longitudinal direction, such that the angular position with respect to the adjacent peripheral region continuously changes, or can comprise longitudinal portions which are offset from each other in the longitudinal direction or border each other discontinuously in respectively different angular positions. Such a profile of the peripheral strip can for example be exhibited by engine bonnets which are trough-shaped in cross-section and extend via their trough peripheries into the side regions of the body, in order to reduce the risk of injury to pedestrians in the event of collisions. If a flanging roller moves along such a peripheral strip, the flanging tool has to follow the different angular positions of the peripheral strip and correspondingly has to be rotated or pivoted about an axis parallel to the longitudinal direction. In addition, the angular position of the tool also generally has to be altered in the course of the flanging steps which are to be successively performed, wherein the tool as a whole is often cumbersome.
In order to flange peripheral strips having a profile which is complex in this sense, it is possible to use flanging tools comprising a plurality of flanging rollers. In this way, it is possible to flange different longitudinal portions using different flanging rollers. However, flanging tools of this type are in many cases voluminous and problematic if the space available is restricted. Not only the plurality of flanging rollers but also supporting them on a bearing structure of the tool contribute to the volume of the tool.
Flanging rollers for closing a hem—so-called final flanging rollers—are advantageously supported spring-elastically. An example of a preferred support of this type is known from DE 100 11 854 A1. The spring-elastic support likewise increases the volume of the tool and increases the complexity and accordingly also the price.